I have built my own Lisa but I have lot of problem for calibrate my printer. When I go to +x axis my hot head go down and when I go to –x axis my hot head go up at begin and go down after. Same thing on y axis.Somebody have had this problem? And how resolve it.

1) Change your firmware to be standard Cartesian.2) After you home figure out what (a,b,c) machine coordinates get you to 0,0,0. Your start_position will be [-a,-b,-c]. Alternatively, make the start_position (0,0,0) and manually move the nozzle to (0,0,0) before the print.3) Download python 2.74) Run segmentize. Feed your cartesian gcode through the program.5) Take the output code and run it on your machine.